CN201561984U - Devices that detect the speed and position of moving objects - Google Patents

Abstract

A device for detecting the speed and position of a moving object, which consists of: installing an electromagnetic induction sensor on the moving object; Metal strips and non-metallic gaps are arranged alternately; the coding section is composed of coding metal strips with a width of L/2 and non-metallic coding gaps. The initial and non-metallic coding gaps of the coding section are non-metallic coding gaps, and their adjacent positions are arranged All of them are non-metallic gaps in the non-coded segment; the middle arrangement constitutes an N-bit code, and the sensor is two groups, and the distance between the two groups is an even multiple of L and greater than the length of the coded segment; each group includes two front and rear distances L/ 2 sensors with odd multiples, the width of the front and rear sensors along the moving direction is L/2. The device is not affected by the external environment, can adapt to harsh external conditions, has high reliability, low maintenance cost, high precision and accuracy of measurement results, and a long detectable distance.

Description

Devices that detect the speed and position of moving objects

technical field

The utility model relates to a device for detecting the speed and position of a moving object.

Background technique

At present, the use of non-contact detection methods to detect the speed and position of moving objects is increasingly widely used. The detection methods generally use return lines, leaking coaxial cables, and ground transponders. The return lines and leaking coaxial cables need to be installed on the ground. The installation of signal sources increases the cost of track maintenance. Although the ground transponder does not need to be connected to the mains, it is still an electronic device that works live, with poor reliability and high maintenance and management costs.

Utility model content

The purpose of this utility model is to provide a device for detecting the speed and position of a moving object. The device is not affected by the external environment, can adapt to harsh external conditions, has high reliability, low maintenance cost, high precision and accuracy of measurement results, and can The detection distance is long.

The utility model realizes its purpose of the invention, and the adopted technical scheme is: a kind of equipment for detecting the speed and position of a moving object, which consists of:

On the ground along the moving direction of the detected moving object, an encoding board is installed, and the moving object is installed with an electromagnetic induction sensor directly above the encoding board; the sensor is connected to the on-board detection device; the encoding board consists of a coding section and a non-coding section Arranged alternately, where:

The non-coding section is composed of unit metal strips and non-metal gaps arranged alternately, and the width of the unit metal strips and non-metal gaps is L;

The coding section is composed of coding metal strips and non-metal coding gaps, the width of the coding metal strips and non-metal coding gaps is L/2; the value of the logic unit corresponding to the coding metal strip is 1, and the corresponding non-metal coding gap The value of the logical unit is 0; the initial position and the non-metallic coding gap of the coding segment are both non-metallic coding gaps, and the non-metallic gaps of the non-coding segment are arranged in its adjacent positions; the coding metal strip and the non-metallic coding gap in the middle position The total length is N*L/2, and the values of the corresponding N logic units are arranged to form an N-bit code, and N is an integer greater than 1;

The sensors are two groups, and the distance between the two groups is an even multiple of L, and is greater than the length of the encoding section; each group of sensors includes two sensors whose distance is an odd multiple of L/2, the front sensor and the rear sensor are along the The width in the moving direction of the object is L/2.

Working process and principle of the present utility model are:

During detection, the sensor generates electromagnetic coupling with the ground encoding plate. When the sensor moves above the metal strip on the encoding plate along with the detected object, the sensor outputs a high-level signal, and when the sensor moves above the non-metallic gap, the sensor output is low. Level signal, as the position of the sensor above the encoding board changes, the sensor outputs a pulse signal consisting of high and low levels, and the electrical signal is analyzed and processed by the on-board detection device to obtain the position and speed of the moving object. The specific determination method is:

The metal strip width and non-metal gap in the non-coding section are alternately arranged and the width is equal to L. When the moving object is moving, the on-board detection device obtains a periodically changing pulse signal composed of high and low levels alternately through the sensor. The time length of the period T of the pulse signal is the time for the detected object to pass through a metal strip width at the current position and an adjacent non-metal gap (the total length is 2L). Therefore, divide 2L by the period T of the pulse signal detected by any sensor to obtain the current speed of the moving object. Correspondingly, at a certain moment, the total number of pulses detected by any sensor from the beginning to this moment is multiplied by 2L, which is the total displacement of the moving object, so as to determine the current position of the moving object (distance from the initial position) .

Since the distance between the front and rear sensors in the sensor group is an odd multiple of L/2, the phase difference of the pulse signals detected by the front and rear sensors is π/4, and the pulse signals output by the two sensors are XORed, A reference pulse signal with a period of T/2 is obtained, the period of the reference pulse signal is reduced by half, the number of pulses is doubled, the width of the encoding plate corresponding to each pulse is reduced by half, and the accuracy of the correspondingly calculated position of the moving object is improved double.

In the coding section, set the width of the coding metal strip and the non-metallic coding gap to L/2, and arrange the metal strips and non-metallic strips according to the required number of coding digits. Each coding section has a unique coding value. One to one correspondence. As the detected object moves to this point, the sensor reads out the code value, and after being processed by the on-board detection device, it gives the exact position of the object corresponding to the current code.

The specific working process and principle of the sensor reading the code value of the code segment is: the reference pulse signal after the XOR output signal of the front and rear sensors of the vehicle detection device is used as the time reference, analyze and read the pulse signals of the two groups of sensors, and analyze and read the pulse signals of the two groups of sensors. The sensor's front (after) pulse signal is compared. When the two groups of sensors are in the non-coding segment, since the distance between the front (rear) sensors of the two groups of sensors is an even multiple of L, the difference between the two groups of signals is an integer multiple of 2π, that is, the two signals are exactly the same, indicating that the sensor group Not in the code segment.

Once the front (rear) sensor in one group of sensors has entered the coding section, because the distance between the two groups of sensors is greater than the length of the coding section, the front (rear) sensor of another group of sensors must be in the non-coding section. At the same time, since the initial position of the coding section is a non-metallic coding gap with a width of L/2, and the adjacent non-metallic gap is a non-coding section, the signal of the sensor at the initial position of the coding section is logic 0, and The other corresponding sensor reading in the non-coding segment that is an even multiple of L apart must be logic 1; that is, when the reading signals of the two front (rear) sensors are inconsistent at the beginning, it indicates that the reading signal is 0 The sensor of the sensor enters the coding section, and the next bit from there is the coding output, and the N-bit logical value read out in turn is the coding value of the coding section; since the unpositioned location of the coding section is also a width of L/2 and is adjacent to the non-metallic gap of the non-coding section, therefore, after the sensor in the coding section reads the N-bit code value, it immediately outputs a logic 0 at the last position, and the distance L is an even number The sensor in the non-coding segment of times must output a logic 1 at this time. If the output is consistent with this, it means that the signal of the code segment is read correctly, and the position corresponding to the code value of the code segment can be output as the detection result. Since there are front and rear sensors in each group, the front sensors in the two groups can form a pair of sensors to obtain an absolute position encoding data in this way, and the rear sensors can also form another pair of sensors to obtain another absolute position. Encoded data, when one pair of sensors is disturbed and unable to output correctly encoded data, the on-board detection device can use the encoded data of another pair of sensors.

Compared with the prior art, the beneficial effects of the utility model are:

1. The utility model quickly and effectively detects the current position and speed of the moving object through the long-distance non-coding segment, and doubles the detection accuracy by using two sensors whose distance is an odd multiple of L/2, and the measurement result has high accuracy. precise.

2. The coding plate as a ground marker is composed of a coded section and a non-coded section. The coded section is used as a mark at a specific position of the moving route, and the coded value of the coded section is read out by comparing the readings of two groups of sensors whose distance is an even multiple of L. Thereby, the absolute position of the place can be obtained, and these specific positions of the moving object on the moving route can be determined. Thereby, the measurement error that may be caused by the inaccurate sensor detection can be corrected by using the non-coded section distance measurement, and the position correction is performed every time a coded section is reached, thereby effectively avoiding the cumulative expansion of the distance measurement error. Therefore, the detection of the utility model The distance measurement range of the method is long, and the measurement error is small.

The front sensor pair and the rear sensor pair in the two groups can independently obtain an absolute position encoding data. When one pair of sensors is disturbed and cannot output the correct encoding data, the on-board detection device can use another encoding data, which further ensures The reliability of the equipment of the utility model and the accuracy of detection results.

3. The device of the present invention is used for speed and position detection of non-contact moving objects. Since the live parts of the equipment are all installed on moving objects, and the metal coding plate installed on the track is a passive device, it can adapt to the harsh conditions of the outside world, and the maintenance cost is very low. Its accuracy, economy and reliability are very high. good.

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the coding plate in the non-coding section of the device according to Embodiment 1 of the utility model and the output signal waveform of the sensor moving in the non-coding section.

Fig. 2 is a schematic diagram of the structure of the device in the first embodiment of the present invention in a coded section and adjacent non-coded sections, and the output signal waveform of the sensor moving on the coded board and the coded sequence in the coded section.

Detailed ways

Embodiment one

Fig. 1, 2 show that a kind of embodiment of the present utility model is, a kind of equipment that detects the speed and position of moving object, it is made up of:

On the ground along the moving direction of the detected moving object, an encoding board is installed, and the moving object is installed with an electromagnetic induction sensor directly above the encoding board; the sensor is connected to the on-board detection device; Segments CB are arranged alternately, where:

The non-coding section CB is composed of unit metal strips 1 and non-metal gaps 0 alternately arranged, and the width of the unit metal strips 1 and non-metal gap 0 is L;

The coding segment CA is composed of a coding metal strip 1A and a non-metal coding gap 0A, the width of the coding metal strip 1A and the non-metal coding gap 0A is L/2; the value of the logic unit corresponding to the coding metal strip 1A is 1, The value of the logical unit corresponding to the non-metallic coding gap 0A is 0; the initial position and the non-metallic coding gap 0A of the coding segment CA are both, and the adjacent positions are all non-metallic gap 0 of the non-coding segment; the middle The total length of the coded metal strip 1A and the non-metallic coded gap 0A of the position is N*L/2, and the values of N logical units corresponding to the arrangement constitute an N-bit code, and N is an integer greater than 1;

The sensors are two groups of S1F, S1B and S2F, S2B, and the distance between the two groups is an even multiple of L, and is greater than the length of the coding section CA; each group of sensors S1F, S1B or S2F, S2B includes two distances between front and rear For a sensor that is an odd multiple of L/2, the width of the front sensors S1F, S2F and the rear sensors S1B, S2B along the moving direction of the object is L/2.

It can be seen from Figure 1 that the distance between the centers of the sensors in the group is 5 times of L/2 in this example. The distance between the centers of the front and rear sensors is an even multiple of L, in this case 10L.

Figure 1 also shows that when all the sensors S1F, S1B, S2F, and S2B are moving in the non-coding section CB, the signals sent by all the sensors S1F, S1B, S2F, and S2B are periodically changing signals, and the front sensors of the two groups The output signals of S1F and S2F are the same, that is, the waveform W1 in Fig. 1, and the output signals of the rear sensors S1B and S2B in the two groups are the same, that is, the waveform W2 in Fig. 1 . The period of waveform W1 or waveform W2 is T, and the waveform W3 is the XOR of waveform W1 and waveform W2 to obtain the reference signal waveform with a period of T/2. L/(T/2) is calculated by the moving object in units of T/2 instantaneous speed. Multiply the total number of pulses of waveform W3 by L/2 to obtain the current moving distance of the moving object.

Figure 2 shows that when the rear sensor S1B of one group of sensors moves from the non-coding segment CB into the coding segment CA and then out of the coding segment CA, the output waveform of the rear sensor S1B is W4; The output waveform of the sensor S2B is W5, and the on-board detection device processes the two groups of waveforms with the reference waveform W3 of this period as the time reference, and obtains the coding sequence X1 and coding sequence X2 in Figure 2 respectively, and converts the coding sequence X1 , X2 are compared, and the time period of the two sequences is consistent, indicating that the rear sensors S1B and S2B are both located in the non-coding segment CB. At the moment when the two sequences are inconsistent, the output value of S1B is 0, and the output value of S2B is 1, indicating that the rear sensor S1B starts to enter the coding section CA. From the inconsistency of the two sequences, the encoded output value sequence X3 of the code segment CA is obtained, and the first bit 0 (start bit) and the last bit 0 (end bit) of the sequence X3 are removed, and the sequence value of the middle segment of the sequence X3 is The coded value of the coded segment, and the absolute position of the moving object is obtained from the coded value.

The output waveform of the front sensor in the two groups of sensors is also exactly the same as that shown in FIG. 2 .

Obviously, the ranging accuracy of the utility model is determined by the width of the unit metal strip 1 of the non-coding section CB and the width of the non-metallic gap O. When the width of the unit metal strip 1 is 50mm, the positioning accuracy of the moving object is 50mm. A two sensor setup within a set increases this accuracy to 25mm. The total length of ranging is equal to the sum of the length of the non-coded segment CB and the length of the coded segment CA multiplied by the number of codes used. If a code segment is set every 200m, the number of code bits in the code segment is 16, and the number of codes is 216, the detectable distance can reach 13107.2km.

Apparently, the number of sensors in the two groups of sensors of the present invention can also be more than 2 M. The width of the M sensors is L/M, and the distance between two adjacent sensors is (K+1)L/M, where K is a non-negative integer. The width of the coded metal strip 1A and the non-metallic coded gap 0A of the coded segment CA is also set to L/M, and the waveforms obtained by M sensors are digitally processed to obtain a reference signal with a period of T/M. In this way, the detection accuracy can be improved to L/M.

In the coding section CA of the utility model, if there are two or more coding metal strips 1A adjacent to each other (there is no non-metallic coding gap 0A in the middle), these adjacent coding metal strips 1A can also adopt an integrated long metal strip Alternative; the same adjacent non-metal coding gap 0A can also be made of an integrated non-metal material.

Claims (1)

1. A device for detecting the speed and position of a moving object, characterized in that: On the ground along the moving direction of the detected moving object, an encoding board is installed, and the moving object is equipped with an electromagnetic induction sensor directly above the encoding board; the sensor is connected to the vehicle-mounted detection device; The non-coding segment (CB) is arranged alternately, where: The non-coding section (CB) is composed of unit metal strips (1) and non-metal gaps (0) alternately arranged, and the width of the unit metal strips (1) and non-metal gaps (0) is L; The coding segment (CA) is composed of coding metal strips (1A) and non-metal coding gaps (0A), and the width of the coding metal strips (1A) and non-metal coding gaps (0A) is L/2; the coding metal strips The value of the logic unit corresponding to (1A) is 1, and the value of the logic unit corresponding to the non-metal coding gap (0A) is 0; the initial position and the non-position of the coding segment (CA) are both non-metal coding gaps (0A), and The adjacent positions are all non-metallic gaps (0) that are non-coding segments; the total length of the coded metal strips (1A) and non-metallic coding gaps (0A) in the middle position is N*L/2, and the corresponding N The values of the logical units constitute an N-bit code, where N is an integer greater than 1; The sensors are two groups (S1F, S1B and S2F, S2B), and the distance between the two groups is an even multiple of L, and is greater than the length of the coding section (CA); each group of sensors (S1F, S1B or S2F, S2B) contains The distance between the front and rear sensors is an odd multiple of L/2, and the width of the front sensor (S1F, S2F) and the rear sensor (S1B, S2B) along the moving direction of the object is L/2.

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